Above is a graph of the miles ran by the runner and the time in minutes it has taken her to complete those miles. Drag the runner across the function F(X)= ln(1000X) to represent how many miles she has run. Then you are able to calculate the speed (Minutes per mile) of the runner by finding the derivative of the graph at that exact point. PC: http://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&uact=8&docid=J0mUftgH9ZefpM&tbnid=8GhTnBSDXjvoTM:&ved=0CAMQjhw&url=http%3A%2F%2Fcommons.wikimedia.org%2Fwiki%2FFile%3AMaudslay_running_trail_1.JPG&ei=-YOHU8T9AoHQkAXXx4DQCA&bvm=bv.68114441,d.aWw&psig=AFQjCNEPX3CzuCmcf7vpcEchex_JfFoOoA&ust=1401476456864835
